tables and figures - sustainable agriculture · web viewtables and figures figure 1. cover crop...

Tables and Figures

Figure 1. Cover crop height (cm) measured on 28 Mar. 2014 and 28 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, Ar. Mean separation was performed by LSD at P < 0.05. n = 3 experimental units. Letters represent differences between means for year x treatment combinations.

Control Winter Peas Bell Beans Mustard Radish0

20

40

60

80

100

120

E

CD CDC

B

DE DE

BB

A

2014 2015

Cover Crop Treatment

Cove

r Crop

Heig

ht (cm

)

1

Figure 2. Cover crop aerial dry biomass (g/m2) sampled on 28 Mar. 2014 and 28 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, Ar. Mean separation was performed by LSD at P < 0.05. n = 3 experimental units. Letters represent differences between means for year x treatment combinations.


50

100

150

200

250

300

350

400

450

E

BC

D

DE DE

C

BC

AB

AA

2014 2015


Cove

r Cro

p Bio

mass

(g/m

2)

2

Table 1. Correlation between cover crop variables and parameters, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR during the winter seasons of 2013-2014 and 2014-2015. For each relationship the Pearson Correlation Coefficients (PCC), p-value, and number of observations (n) are included in the table. Bolded cells are considered significant with a p-value under 0.10. Analysis was conducted with PROC CORR in SAS 9.4.

YearCover Crop N%

Cover Crop C%

Cover Crop C/N

Cover Crop Height

Cover Crop Biomass

Cover Crop Total N

Weedy Biomass

Year PCC 1 -0.06557 0.75449 0.22321 0.39712 0.7708 0.40133 .p-value 0.7306 <.0001 0.2358 0.0298 <.0001 0.0279 .n 30 30 30 30 30 30 30 15PCC -0.06557 1 0.36969 -0.9515 -0.42953 0.0819 0.70129 -0.04553p-value 0.7306 0.0444 <.0001 0.0178 0.667 <.0001 0.872n 30 30 30 30 30 30 30 15PCC 0.75449 0.36969 1 -0.19878 0.19252 0.67685 0.60447 -0.41727p-value <.0001 0.0444 0.2923 0.3081 <.0001 0.0004 0.1217n 30 30 30 30 30 30 30 15PCC 0.22321 -0.9515 -0.19878 1 0.53797 0.13716 -0.54879 -0.13682p-value 0.2358 <.0001 0.2923 0.0022 0.4698 0.0017 0.6268n 30 30 30 30 30 30 30 15PCC 0.39712 -0.42953 0.19252 0.53797 1 0.57896 0.0723 -0.55369p-value 0.0298 0.0178 0.3081 0.0022 0.0008 0.7042 0.0322n 30 30 30 30 30 30 30 15PCC 0.7708 0.0819 0.67685 0.13716 0.57896 1 0.69956 -0.61327p-value <.0001 0.667 <.0001 0.4698 0.0008 <.0001 0.015n 30 30 30 30 30 30 30 15PCC 0.40133 0.70129 0.60447 -0.54879 0.0723 0.69956 1 -0.30185p-value 0.0279 <.0001 0.0004 0.0017 0.7042 <.0001 0.2742n 30 30 30 30 30 30 30 15PCC . -0.04553 -0.41727 -0.13682 -0.55369 -0.61327 -0.30185 1p-value . 0.872 0.1217 0.6268 0.0322 0.015 0.2742n 15 15 15 15 15 15 15 15

Weedy Biomass

Cover Crop Tissue N%

Cover Crop Tissue C%

Cover Crop Tissue C/N Ratio

Cover Crop Height

Cover Crop Biomass

Cover Crop Total Biomass N

3

Figure 3. Relationship between cover crop height and cover crop dry weight biomass, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR during the winter seasons of 2013-2014 and 2014-2015.

20.00 40.00 60.00 80.00 100.00 120.000.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00

f(x) = 3.12171570460236 x + 58.5666612553133R² = 0.335207106087299

Height (cm)

Bom

ass (

g/m

2)

4

Figure 4. Cover crop and weedy dry biomass (g/m2), sampled on 28 Mar. 2015, 128 days after planting in a high tunnel in Fayetteville, Ar. Mean separation was performed by LSD at P < 0.05. n = 3 experimental units. Upper-case letters represent mean separation between the cover crop biomass and lower-case letters represent mean separation between the weedy biomass measurements.


50

100

150

200

250

300

350

400

450

a

c

b

ccC

B

B

A

A

Weedy Biomass Cover Crop Biomass


Dry W

t Bio

mass

(g/m

2)

5

Figure 5. Relationship between cover crop dry weight biomass and weedy biomass, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR during the winter seasons of 2013-2014 and 2014-2015.

200.00 220.00 240.00 260.00 280.00 300.00 320.00 340.00 360.00 380.00 400.000.0

50.0

100.0

150.0

200.0

250.0

300.0

f(x) = − 0.689754407853696 x + 314.515460047499R² = 0.376095114566928

Cover Crop Biomass (g/m2)

Wee

dy B

omas

s (g/

m2)

6

Table 2. Nutrient content of above-ground cover crop biomass sampled on 28 Mar. 2014 and 20 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, Ar. F-test conducted to determine interaction effects (n=3, p < 0.05).

Treatment % mg/kg

Year P K Ca Mg S Na Fe Mn Zn Cu B

Control0.41

5 3.07 1.21 0.164 0.349 214.1 1311.0 54.5 33.1 27.6 18.9

20140.44

9 3.19 1.15 0.169 0.372 173.7 991.0 39.8 35.9 36.2 19.4

20150.38

0 2.94 1.27 0.160 0.327 254.5 1631.0 69.2 30.3 19.1 18.4

Winter Peas0.36

4 3.68 1.35 0.280 0.253 587.5 352.2 53.8 78.6 17.9 20.5

20140.36

6 4.17 1.30 0.277 0.250 415.1 623.9 58.2 75.4 25.2 19.8

20150.36

1 3.20 1.39 0.283 0.255 759.9 80.6 49.4 81.8 10.6 21.3

Bell Beans0.31

5 3.47 1.22 0.216 0.208 1873.9 198.4 54.2 67.8 21.3 22.1

20140.35

7 4.26 1.14 0.219 0.232 1243.0 308.3 52.0 74.5 29.0 21.8

20150.27

3 2.67 1.30 0.214 0.183 2504.7 88.6 56.3 61.2 13.7 22.3

Mustard0.37

2 3.08 1.49 0.176 0.590 193.9 675.5 37.8 32.4 21.6 29.4

20140.39

6 2.72 1.70 0.208 0.583 176.6 1243.3 55.9 42.5 38.0 27.7

20150.34

8 3.44 1.28 0.145 0.597 211.2 107.8 19.8 22.4 5.3 31.1

Radish0.46

4 3.33 1.90 0.197 0.596 749.1 537.6 27.1 28.7 17.7 27.2

20140.49

9 3.33 2.24 0.227 0.674 603.5 1052.2 42.2 35.6 31.8 29.0

20150.43

0 3.34 1.56 0.167 0.518 894.6 23.0 12.0 21.7 3.5 25.3

* ** ** * * * ** ** * * **7

* indicates Trt main effect at p < 0.05

** indicates Year by Trt interaction effect at p < 0.05

8

Table 3. Cover crop aerial tissue C and N content from samples collected from above-ground cover crop biomass on 28 Mar. 2014 and 20 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, AR. Treatment

Year N% C% C/N ratio

Control1.75 Cz

38.81

23.48 B

20141.82

38.56

cd

22.66

20151.68

39.06 c

24.29

Winter Peas3.78 A

41.17

11.01 C

20143.81

38.67

cd

10.32

20153.75

43.67 a

11.70

Bell Beans3.14 B

41.13

13.43 C

20143.28

38.83

cd

12.05

20153.00

43.44

ab

14.82

Mustard1.54

CD

39.17

25.90

AB

20141.60

36.93

de

23.26

20151.48

41.41 b

28.53

Radish1.37 D

38.56

28.79 A

20141.40

35.52 e

25.85

20151.35

41.59

ab

31.74

* ** *

* F-test indicates Trt main effect a p < 0.001

9

** F-test indicates Year*Trt interaction effect at p < 0.001 zUpper-case letters represent means separation between values within the column for main effects. Lower case letters indicate mean separation between values within a column for the interaction effects. Mean separation was performed by LSD at p < 0.05. N = 3.

10

Figure 6. Cover crop aerial tissue N concentration (%) mean values from years 2014 and 2015 pooled. Aerial biomass was sampled on 28 Mar. 2014 and 29 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, AR. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units. Letters represent differences between treatment means.


0.5

1

1.5

2

2.5

3

3.5

4

C

A

B

CDD


Cov

er C

rop

Bio

mas

s N C

once

ntra

tion

(%)

11

Figure 7. Aerial tissue C concentration sampled from treatments on 28 Mar. 2014 and 29 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, AR. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units. Letters represent differences between means for year x treatment combinations.


32

34

36

38

40

42

44

CD CD CD

DE

E

C

A AB

B AB

2014 2015


Cove

r Cro

p Bi

omas

s C%

12

Figure 8. Cover crop biomass N (g/m2) calculated from aerial biomass sampled on 28 Mar. 2014 and 29 Mar. 2015, 132 and 128 days after planting, respectively, in a high tunnel in Fayetteville, AR. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units. Letters represent differences between means for year x treatment combinations.


2

4

6

8

10

12

E

A

C

DE DE

CD

AAB

BC

C

2014 2015


Total

Bio

mass

N (g

/m2)

13

Figure 9. Relationship between cover crop aerial tissue N and cover crop height, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR and sampled on 28 Mar. 2014 and 29 Mar. 2015, 132 and 128 days after planting, respectively.

1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.500.00

20.00

40.00

60.00

80.00

100.00

120.00

f(x) = − 10.5524206729912 x + 81.9505173897588R² = 0.18446231289384


Heig

ht (c

m)

14

Figure 10. Relationship between cover crop above-ground tissue C and cover crop biomass, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR and sampled on 28 Mar. 2014 and 29 Mar. 2015, 132 and 128 days after planting, respectively.

32.00 34.00 36.00 38.00 40.00 42.00 44.00 46.000.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00

f(x) = 32.2887361826929 x − 1046.00868743628R² = 0.458209886025233


Biom

ass (

g/m

2)

15

Table 4. ANOVA table of interaction between cover crop treatment (CC) and year on soil organic matter (SOM) and bulk density (BD), measured on 25 April 2014 and 28 April 2015. Significant main effects where P < 0.05 are bolded and shaded.

Factor DF SOM BDYear 1 <0.0001 0.0002CC 4 0.7447 0.4945Year X CC 4 0.8352 0.1535Block(Year) 4 0.7315 0.0412

Soil Variables (P < F)

16

Table 5. ANOVA for interaction between cover crop treatment (CC) and date on soil C% soil N% and soil C/N ratio, from soil samples collected on 28 Mar. 2014, 25 April 2014, 28 Mar. 2015, and 28 April 2015. Highest-order interactions or significant main effects where P < 0.05 are bolded and shaded.

Factor DF N% C% C/NDate 3 0.0822 0.001 <.0001CC 4 0.4996 0.0845 0.0077Date X CC 4 0.2309 0.0864 0.0322Block(Date) 8 0.2007 0.45 0.7474


17

Figure 11. Soil C/N ratio measured from 15 cm soil cores collected on sampling dates of 28 Mar. 2014, 26 April 2014, 28 Mar. 2015, and 28 April 2015 in a high tunnel in Fayetteville, AR. March sampling dates were prior to cover crop incorporation and April dates were 30 days after incorporation. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units.

2014-Mar 2014-Apr 2015-Mar 2015-Apr9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

EFGH

FGHI

DEFGH DEFGHEFGH

I

BC

I

CDE

GHI

AB

HI

CDEFGDEFGH

BCD

DEFGHCDEFG

CDEF

A

GHI

Control Winter Peas Bell Beans Mustard Radish

Sampling Date

Soil

C/N

Ratio

18

Figure 12. Relationship between cover crop biomass N and soil C/N ratio, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR. Soil C/N ratio was measured from 15 cm soil cores collected on sampling dates of 28 Mar. 2014, 26 April 2014, 28 Mar. 2015, and 28 April.

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.08.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

f(x) = − 0.101747132240812 x + 10.7909048684171R² = 0.310964956014349

Cover Crop Biomass N (g/m2)

Soil

C/N

Ratio

19

Table 6. Correlation between cover crop variables and soil variables, as measured from Austrian winter peas, bell beans, ‘Kodiak’ mustard, and ‘Daikon’ radish grown in a high tunnel in Fayetteville, AR during the winter seasons of 2013-2014 and 2014-2015. For each relationship the Pearson Correlation Coefficients (PCC), p-value, and number of observations (n) are included in the table. Bolded cells are considered significant with a p-value under 0.10.

Soil N% Soil C%Soil C/N Ratio

PCC 0.11101 -0.27999 -0.54865p-value 0.5592 0.134 0.0017n 30 30 30PCC -0.35578 -0.54193 -0.47803p-value 0.0537 0.002 0.0075n 30 30 30PCC -0.10372 0.20504 0.42914p-value 0.5855 0.2771 0.018n 30 30 30PCC -0.06041 0.03715 0.08939p-value 0.7512 0.8455 0.6386n 30 30 30PCC -0.23142 -0.33711 -0.27434p-value 0.2185 0.0685 0.1424n 30 30 30PCC -0.03062 -0.37248 -0.55765p-value 0.8724 0.0427 0.0014n 30 30 30



Cover Crop Tissue C/N RatioCover Crop Height

Cover Crop Biomass

Cover Crop Biomass N

20

Figure 13. Soil pH measured from 15 cm soil core samples collected on 28 Mar. 2014, 25 April 2014, 8 Aug. 2014, 7 Nov. 2014, 28 Mar. 2015, 28 April 2015, 12 Aug. 2015, and 12 Nov. 2015. March sampling dates are prior to cover crop incorporation, April dates are 30 days after incorporation, August dates are after tomato cropping, and November dates are after broccoli cropping in a high tunnel in Fayetteville, AR. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units. Upper-case letters represent means separation among sampling dates and lower-case letters represent means separation among cover crop treatments.

2014-Mar 2014-Apr 2014-Agu 2014-Nov 2015-Mar 2015-Apr 2015-Aug 2015-Nov6.0

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

ABb

Ab

ABb

BCbCb

BCb

Cb

Db

ABb AbABb

BCbCb

BCb Cb

Db

ABa Aa

ABa

BCa

CaBCa

Ca

Da

ABa

AaABa

BCa

CaBCa

Ca

Da

ABa

AaABa

BCaCa BCa Ca

Da


Sampling Date

Soil

pH

21

Table 7. Statistical analysis of variance for interaction between cover crop treatment and sampling date for the variables pH, EC, and nutrient levels (P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B) measured from 15 cm soil core samples collected on 28 Mar. 2014, 25 April 2014, 8 Aug. 2014, 7 Nov. 2014, 28 Mar. 2015, 28 April 2015, 12 Aug. 2015, and 12 Nov. 2015. March sampling dates are prior to cover crop incorporation, April dates are 30 days after incorporation, August dates are after tomato cropping, and November dates are after broccoli cropping in a high tunnel in Fayetteville, AR. Highest-order interactions or significant main effects are bolded and shaded.

Factor DF pH EC P K Ca Mg SDate 7 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001Cover Crop 4 <.0001 0.3642 0.7329 0.0001 0.1042 0.0017 0.2144Date X Cover Crop 28 0.9954 0.0145 0.9991 0.7126 0.9997 0.507 0.0178Block(Date) 16 0.0002 <.0001 0.0849 0.0144 0.0143 <.0001 <.0001

Factor DF Na Fe Mn Zn Cu BDate 7 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001Cover Crop 4 0.0625 0.0063 0.0722 0.8279 0.0847 0.0025Date X Cover Crop 28 0.1239 1 0.9784 0.9989 1 0.9462Block(Date) 16 <.0001 0.025 <.0001 0.0005 0.173 0.3322



22

Figure 14. Soil EC (dS/m) measured from 15 cm soil core samples collected on 28 Mar. 2014, 25 April 2014, 8 Aug. 2014, 7 Nov. 2014, 28 Mar. 2015, 28 April 2015, 12 Aug. 2015, and 12 Nov. 2015. March sampling dates are prior to cover crop incorporation, April dates are 30 days after incorporation, August dates are after tomato cropping, and November dates are after broccoli cropping in a high tunnel in Fayetteville, AR. Mean separation was performed by LSD at P < 0.05. N = 3 experimental units.

2014-Mar 2014-Apr 2014-Aug 2014-Nov 2015-Mar 2015-Apr 2015-Aug 2015-Nov60

80

100

120

140

160

180

200

220

240

260

280

EFG EFGDEFG

EFG EFGEFG

DE

BC

EFG

CD

EFGDEFG

EFGDEFG

EFG

BC

EFG EFGEFG

EFGEFG EFG

DEFG

B

EFG EFG

DEFDEFG

G FG

DEFG

BC

EFGEFG

DEFG DEFG

EFG FG EFG

A


Sampling Date

Soil

EC (d

S/m

)

23

Figure 2.1. Tomato leaf chlorophyll estimate (SPAD) mean values from tomatoes grown in a high tunnel in Fayetteville, AR in 2014 and 2015 following cover crop treatments. Upper case letters represent means separation at P < 0.05, N = 3. Means comparison was carried out using Student’s t test.

Control Winter Peas Bell Beans Mustard Radish46.00

47.00

48.00

49.00

50.00

51.00

52.00

B

A

AB

B

AB


Chol

orph

yll E

stim

ate

(SPA

D Un

its)

24

Figure 2.3. Tomato foliar N concentration measured from leaf samples collected in 2014 and 2015 from tomatoes grown in a high tunnel in Fayetteville, AR after winter cover crop treatments. Means comparison using Student’s t test at P < 0.05. Bars represent standard error from the mean.

2014 20150.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

NS

B

AB B B

ControlWinter PeaBell BeanMustardRadish

Year

Tom

ato

Folia

r N%

25

Figure 2.6. Tomato yield per plant measured from tomatoes grown in 2014 and 2015 in a high tunnel in Fayetteville, AR following winter cover crop treatments. No significant differences between treatments was detected at P < 0.10. Bars represent standard error of the mean.

2014 20150.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00


Year

Tom

ato

Yield

per

Plan

t (kg

)

26

Figure 2.11. Broccoli foliar N concentration measured on 6 Nov. 2014 and 5 Nov. 2015 from broccoli grown in a high tunnel in Fayetteville, AR following tomatoes which were preceded by winter cover crop treatments. No significant differences between treatments was detected at P < 0.05. Bars represent standard error from the mean.

27

2014 20152.5

2.6

2.7

2.8

2.9

3.0

3.1

3.2

3.3


Year

Broc

coli F

oliar

N%

Figure 2.12. Broccoli plant fresh weight biomass (g) across years measured on 7 Nov. 2014 and 9 Nov. 2015 from broccoli grown in a high tunnel in Fayetteville, AR following tomatoes which were preceded by winter cover crop treatments. Upper case letters represent means separation by Student’s t Test at P < 0.05, N=3.

Control Winter Pea Bell Bean Mustard Radish0

100

200

300

400

500

600

700

800

900

B

A

AB ABA


Fres

h W

eight

Bro

ccol

i Plan

t Bio

mas

s (g)

28

Figure 2.13. Broccoli total yield (kg) per plot, with harvest occurring through the month of Oct. in 2014 and 2015 from broccoli grown in a high tunnel in Fayetteville, AR following tomatoes which were preceded by winter cover crop treatments. No differences were detected between treatments means with Student’s t-test at P < 0.05, N = 3. Bars represent standard error from the mean.

2014 20151.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4


Year

Tota

l Yiel

d pe

r Plo

t (kg

)

29

Figure 2.14. Broccoli average head weight (g) from harvest occurring through the month of Oct. in 2014 and 2015 from broccoli grown in a high tunnel in Fayetteville, AR following tomatoes which were preceded by winter cover crop treatments. No differences were detected between treatments means with Student’s t-test at P < 0.05, N = 3. Bars represent standard error from the mean.

30

2014 201560

80

100

120

140

160

180


Year

Broc

coli A

vera

ge H

ead

Weig

ht (g

)

APPENDIX A

Figure A.1.

31

Figure A.2

32

tables and figures - sustainable agriculture · web viewtables and figures figure 1. cover crop...

Documents